<?php
class Model_Bgtask_Signal extends Model
{
	protected static $_instance =  null;
	/**
     * @return Model_News
     */
	static public function getInstance(){
        if(is_null(self::$_instance))	
           self::$_instance = new self('Bgtask_Signal');     
        return self::$_instance;   
    }
	/**
	 * Remove signals for object
	 * @param integer $pid
	 * @return void
	 */
	public function clearSignals($pid){
		$this->_db->delete($this->table() , '`pid` = ' . intval($pid));
	}
}